No abstract available

[en] We study the dynamics of surface and space charges induced by a fast charged particle traversing a layer of insulator or conductor. We show that the polarization of the layer is of an oscillatory nature, and the net induced charge in an insulating layer and in a layer of a conductor thinner than u/2πσ, where u is the particle velocity and σ is the DC conductivity, remains zero at all stages of the motion. In a conducting layer thicker than u/2πσ the net induced charge is also time independent but, as with a half-space, is equal to the charge of the particle with the opposite sign

[en] In field calculations involving corona discharges, the difficulties associated with practical electrode-geometries are compounded by the presence of space charges so that numerical methods have to be used to obtain accurate solutions. Despite their accuracy, these methods do not give insights into the physical processes which control the electrical phenomena. The only useful analytic solution for charge-free situations is that for hyperboloid-plane geometries, but this is a Laplacian solution which does not allow for the major distortion of the field-line geometry that occurs in the presence of ionic charges. Nevertheless, it remains the only reasonable way of giving mathematical expressions for the various field-variables. Recently the length of field-lines has been shown to be linked to the planar charge-density distribution by means of the charge-drift formula. The theory makes the simplifying assumption of the operation of a uniform electric field during the ionic drift from point to plane. This is an oversimplification, and the true field can only be found numerically. However, as an intermediate, the analytic solution of the hyperboloidal geometry can be used to predict an algebraic form for the planar charge-density distribution. It is with this derivation and the subsequent comparison of the form with the empirical (measured) values that this paper is concerned

[en] The results of formerly leaded connected with radioactive-stimulated electric conductivity of polyethylene depurated iodine, showed, that conductivity n-species raising on several orders up to senses, which typical for metals. Heating of depurated samples of irradiated PE up to 400 K doesn't chemical general picture, that testify about chemical interaction between iodine and polymer matrix by radiolysis. For the purpose of explanation experiment results made the quantum-chemical accounts by method AM1. Accounts, made for models PE both original and containing iodine atoms, added to alkyl radicals. Used models of polymer, which containing 50 monomeric sections and having terminal vinyl group. Great electronic conductivity in radiation-processed polyethylene, depurated by iodine atoms, originated in consequence of approximation line of zone repulsion negative charges to electronic membranes hydrogen atoms, that in turn, stipulate significant raise of negative charges, localized on carbon atoms

[en] The field of a magnetic pointlike monopole acts in a similar way on a charged Dirac particle as the field of a very strong electric point charge. To explore this parallel it is constructed a field solution for an extended magnetic-charge distribution. In contrast to what is found for extended electric charges, the Hamiltonian remains nonself-adjoint for an extended magnetic monopole. This suggests that there exist a fundamental difference between the two cases. In particular, the appearance of undefined states for point monopoles is not a consequence of the mere strength of the magnetic-monopole charge, which has a minimum value fixed by Dirac's quantization condition

[en] An illustrative example is presented concerning Thomson's theorem on the minimum energy of the equilibrium charge distribution on conductors. The theorem is used to find the density of the induced surface charge in the classical case of a point charge in front of an infinite planar conductor. The energy functional of the system can be minimized directly by simple considerations. (letters and comments)

[en] An improved space-charge-limited emission algorithm has been developed and tested for use in particle-in-cell codes. Comparisons to established and accepted techniques of modeling space-charge-limited emission demonstrate the new technique to be accurate and efficient. Moreover, the new technique is very insensitive to mesh resolution

No abstract available

[en] The nature of the electrical transport mechanism for carrier transport in pure bis {2-(2-hydroxyphenyl) benzoxazolate} zinc [Zn(hpb)₂] has been studied by current-voltage measurements of samples at different thicknesses and at different temperatures. Hole-only devices show ohmic conduction at low voltages and space charge conduction at high voltages. The space charge conduction is clearly identifiable with a square law dependence of current on voltage as well as the scaling of current inversely with the cube of thickness. With a further increase in voltage, the current increases with a V^m dependence with m varying with temperature typical of trap limited conduction with an exponential distribution of trap states. From the square law region the effective charge carrier mobility of holes has been evaluated as 2.5 x 10^-11 m² V^-1 s^-1. Electron-only devices however show electrode limited conduction, which was found to obey the Scott-Malliaras model of charge injection.

[en] We have studied the target thickness (rho x) dependence of the convoy electron yield Y/sub e/(q/sub f/) for the incident projectiles of nickel ions (charge q/sub i/⁺) (15.6 MeV/u) with q/sub i/ = 28 and 27 on carbon foils in coincidence with outgoing projectiles with charge q/sub f/ = 28 and 27. Simultaneously the charge state evolution F(q/sub f/, rho x) dependence on the incident charge q/sub i/ has been measured. For this collision system the charge state distribution equilibrates for target thicknesses > 650 μg/cm². In the framework of a model for convoy electron production the rho x dependence of the yield Y/sub e/ (q/sub i/,q/sub f/) can be explained if one introduces and electron transport length λ/sub c/ which is much larger than the attenuation length λ/sub e/ of free electrons